May: Copper-filled Thermal Vias

How deep is a dimple of copper-filled laser vias?

Depressions of copper-filled laser vias which mostly result from unfavorable hole geometries are referred to as dimple. The dimple depth is 0 to 25 µm, depending on the ratio of hole depth to hole diameter.

Can laser vias be directly connected to a copper inlay?

The great advantage of the inlay technology is the connection of inlay with copper-filled laser vias. This can be used to achieve the thermal resistance of a PCB of < 0.1 K/W, for example by means of a bilateral connection of laser vias to an inlay.

What is the diameter of a copper-filled laser via?

Laser vias which are used for the transmission of high currents and power losses have a diameter of 120 µm − 160 µm in standard applications.

What is the maximum thickness of the dielectric when using laser vias?

The maximum insulation distance is calculated from the hole depth and the via diameter. The basis is an aspect ratio of 0.8:1. With a drilling diameter of 150 µm and a copper thickness of 18 µm, the maximum thickness of the dielectric remains 100 µm.

How much power dissipation can be dissipated via laser vias?

With optimum connection to the heat sink, with a via field of 9 x 9 mm, for example with 500 laser vias, it is possible to conduct up to 500 W power dissipation through the PCB with a ∆T <20K.

What electrical resistance has a thermal via?

The electrical resistance of a copper-filled laser via depends on diameter and hole depth. With a typical diameter of 150 µm and a hole depth of 100 µm, a completely filled via has an electrical resistance of approx. 0.1 mΩ.

What is the minimum distance required for placing laser vias next to each other?

For vias with identical potential, minimum web widths of 250 µm can be implemented. For a via diameter of 150 µm, the minimum distance (from hole center to hole center) is thus 400 µm.

Why are laser vias are completely filled if possible at SCHWEIZER?

Completely filled laser vias allow direct soldering of power components on a via field. This direct type of heat dissipation offers great advantages in comparison with non-filled laser vias as in this case the heat must be spreaded first before it can be dissipated downward through the laser vias.